Warn users and delete user accounts after period of inactivity

src/backend/app/auth/auth_routes.py

@@ -133,7 +133,8 @@ async def get_or_create_user(
                 )
                 ON CONFLICT (id)
                 DO UPDATE SET
-                    profile_img = EXCLUDED.profile_img
+                    profile_img = EXCLUDED.profile_img,
+                    last_login_at = NOW()
                 RETURNING id, username, profile_img, role
             )
 

src/backend/app/db/models.py

@@ -161,6 +161,7 @@ class DbUser(BaseModel):
     projects_mapped: Optional[list[int]] = None
     api_key: Optional[str] = None
     registered_at: Optional[AwareDatetime] = None
+    last_login_at: Optional[AwareDatetime] = None
 
     # Relationships
     project_roles: Optional[dict[int, ProjectRole]] = None  # project:role pairs
@@ -208,12 +209,12 @@ async def one(cls, db: Connection, user_identifier: int | str) -> Self:
                 sql,
                 {"user_identifier": user_identifier},
             )
-            db_project = await cur.fetchone()
+            db_user = await cur.fetchone()
 
-        if db_project is None:
+        if db_user is None:
             raise KeyError(f"User ({user_identifier}) not found.")
 
-        return db_project
+        return db_user
 
     @classmethod
     async def all(

src/backend/app/users/user_crud.py

@@ -16,3 +16,102 @@
 #     along with FMTM.  If not, see <https:#www.gnu.org/licenses/>.
 #
 """Logic for user routes."""
+
+from datetime import datetime, timedelta, timezone
+from textwrap import dedent
+
+from fastapi import Request
+from loguru import logger as log
+from osm_login_python.core import Auth
+from psycopg import Connection
+from psycopg.rows import class_row
+
+from app.auth.providers.osm import get_osm_token, send_osm_message
+from app.db.models import DbUser
+
+WARNING_INTERVALS = [21, 14, 7]  # Days before deletion
+INACTIVITY_THRESHOLD = 2 * 365  # 2 years approx
+
+
+async def process_inactive_users(
+    db: Connection,
+    request: Request,
+    osm_auth: Auth,
+):
+    """Identify inactive users, send warnings, and delete accounts."""
+    now = datetime.now(timezone.utc)
+    warning_thresholds = [
+        (now - timedelta(days=INACTIVITY_THRESHOLD - days))
+        for days in WARNING_INTERVALS
+    ]
+    deletion_threshold = now - timedelta(days=INACTIVITY_THRESHOLD)
+
+    osm_token = get_osm_token(request, osm_auth)
+
+    async with db.cursor() as cur:
+        # Users eligible for warnings
+        for days, warning_date in zip(
+            WARNING_INTERVALS, warning_thresholds, strict=False
+        ):
+            async with db.cursor(row_factory=class_row(DbUser)) as cur:
+                await cur.execute(
+                    """
+                    SELECT id, username, last_login_at
+                    FROM users
+                    WHERE last_login_at < %(warning_date)s
+                    AND last_login_at >= %(next_warning_date)s;
+                    """,
+                    {
+                        "warning_date": warning_date,
+                        "next_warning_date": warning_date - timedelta(days=7),
+                    },
+                )
+                users_to_warn = await cur.fetchall()
+
+            for user in users_to_warn:
+                await send_warning_email_or_osm(user.id, user.username, days, osm_token)
+
+        # Users eligible for deletion
+        async with db.cursor(row_factory=class_row(DbUser)) as cur:
+            await cur.execute(
+                """
+                SELECT id, username
+                FROM users
+                WHERE last_login_at < %(deletion_threshold)s;
+                """,
+                {"deletion_threshold": deletion_threshold},
+            )
+            users_to_delete = await cur.fetchall()
+
+        for user in users_to_delete:
+            log.info(f"Deleting user {user.username} due to inactivity.")
+            await DbUser.delete(db, user.id)
+
+
+async def send_warning_email_or_osm(
+    user_id: int,
+    username: str,
+    days_remaining: int,
+    osm_token: str,
+):
+    """Send warning email or OSM message to the user."""
+    message_content = dedent(f"""
+    ## Account Deletion Warning
+
+    Hi {username},
+
+    Your account has been inactive for a long time. To comply with our policy, your
+    account will be deleted in {days_remaining} days if you do not log in.
+
+    Please log in to reset your inactivity period and avoid deletion.
+
+    Thank you for being a part of our platform!
+    """)
+
+    send_osm_message(
+        osm_token=osm_token,
+        osm_id=user_id,
+        title="FMTM account deletion warning",
+        body=message_content,
+    )
+    log.info(f"Sent warning to {username}: {days_remaining} days remaining.")

src/backend/app/users/user_routes.py

@@ -19,16 +19,18 @@
 
 from typing import Annotated, List
 
-from fastapi import APIRouter, Depends, Response
+from fastapi import APIRouter, Depends, Request, Response
 from loguru import logger as log
 from psycopg import Connection
 
+from app.auth.providers.osm import init_osm_auth
 from app.auth.roles import mapper, super_admin
 from app.db.database import db_conn
 from app.db.enums import HTTPStatus
 from app.db.enums import UserRole as UserRoleEnum
 from app.db.models import DbUser
 from app.users import user_schemas
+from app.users.user_crud import process_inactive_users
 from app.users.user_deps import get_user
 
 router = APIRouter(
@@ -83,3 +85,15 @@ async def delete_user_by_identifier(
     await DbUser.delete(db, user.id)
     log.info(f"User {user.id} deleted successfully.")
     return Response(status_code=HTTPStatus.NO_CONTENT)
+
+
+@router.post("/process-inactive-users")
+async def delete_inactive_users(
+    request: Request,
+    db: Annotated[Connection, Depends(db_conn)],
+    current_user: Annotated[DbUser, Depends(super_admin)],
+    osm_auth=Depends(init_osm_auth),
+):
+    """Identify inactive users, send warnings, and delete accounts."""
+    await process_inactive_users(db, request, osm_auth)
+    return Response(status_code=HTTPStatus.NO_CONTENT)

src/backend/migrations/005-add-user-lastloginat.sql

@@ -0,0 +1,38 @@
+-- ## Migration add some extra fields.
+-- * Add last_login_at to users.
+-- * Remove NOT NULL constraint from author_id in projects.
+
+-- Related issues:
+-- https://github.com/hotosm/fmtm/issues/1999
+
+-- Start a transaction
+
+BEGIN;
+
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1
+        FROM information_schema.columns
+        WHERE table_name = 'users'
+          AND column_name = 'last_login_at'
+    ) THEN
+        ALTER TABLE users ADD COLUMN last_login_at TIMESTAMPTZ DEFAULT now();
+    END IF;
+END $$;
+
+DO $$
+BEGIN
+    IF EXISTS (
+    SELECT 1
+    FROM information_schema.columns
+    WHERE table_name = 'projects'
+        AND column_name = 'author_id'
+        AND is_nullable = 'NO'
+    ) THEN
+        ALTER TABLE projects ALTER COLUMN author_id DROP NOT NULL;
+    END IF;
+END $$;
+
+-- Commit the transaction
+COMMIT;

src/backend/migrations/init/fmtm_base_schema.sql

@@ -247,7 +247,7 @@ CREATE TABLE public.projects (
     id integer NOT NULL,
     organisation_id integer,
     odkid integer,
-    author_id integer NOT NULL,
+    author_id integer,
     name character varying,
     short_description character varying,
     description character varying,
@@ -357,7 +357,8 @@ CREATE TABLE public.users (
     tasks_invalidated integer NOT NULL DEFAULT 0,
     projects_mapped integer [],
     api_key character varying,
-    registered_at timestamp with time zone DEFAULT now()
+    registered_at timestamp with time zone DEFAULT now(),
+    last_login_at timestamp with time zone DEFAULT now()
 );
 ALTER TABLE public.users OWNER TO fmtm;
 

src/backend/migrations/revert/005-add-user-lastloginat.sql

@@ -0,0 +1,35 @@
+-- * Remove last_login_at from users.
+-- * Restore NOT NULL constraint on author_id in projects.
+
+-- Start a transaction
+BEGIN;
+
+-- Remove last_login_at column from users
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1
+        FROM information_schema.columns
+        WHERE table_name = 'users'
+          AND column_name = 'last_login_at'
+    ) THEN
+        ALTER TABLE users DROP COLUMN last_login_at;
+    END IF;
+END $$;
+
+-- Restore NOT NULL constraint on author_id in projects
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1
+        FROM information_schema.columns
+        WHERE table_name = 'projects'
+          AND column_name = 'author_id'
+          AND is_nullable = 'YES'
+    ) THEN
+        ALTER TABLE projects ALTER COLUMN author_id SET NOT NULL;
+    END IF;
+END $$;
+
+-- Commit the transaction
+COMMIT;